package main

func main() {

}

func uniqueOccurrences(arr []int) bool {
	all := make([]int, 2002)
	for _, value := range arr {
		all[1000+value] += 1
	}
	allTime := make([]bool, 1001)
	for _, value := range all {
		if value == 0 {
			continue
		}
		if allTime[value] {
			return false
		}
		allTime[value] = true
	}
	return true
}
